In general, aerogel is a high porosity material having high porosity of about 90% to about 99% in solids that are known up to date. A silica precursor solution is subjected to sol-gel polymerization reaction to prepare gel, and then, a drying process is performed on the prepared gel under supercritical or atmospheric conditions to obtain the aerogel. That is, the aerogel has a pore structure filled with air.
Such the aerogel is lightweight and has physical properties such as heat insulation and sound absorption due to the unique pore structure in which 90% to 99% of an internal space is empty. The greatest advantage of the above-described advantages is the high heat insulation having thermal conductivity of 30 mW/m·k or less, which is significantly lower than thermal conductivity of 36 mW/m·k that is thermal conductivity of an organic insulation material such as conventional Styrofoam and the like.